A Pakistani astronaut will become the first foreign national aboard China’s Tiangong space station, as Beijing steps up space diplomacy amid a burgeoning battle with the United States for supremacy in orbit.

China has launched three astronauts to replace the crew on the Chinese Tiangong space station. The Shenzhou 20 spaceship took off as planned atop China’s workhorse Long March 2F rocket at 5:17 p.m. local time (0917 GMT).

A crew of Chinese astronauts headed for orbit Thursday to begin a six-month-long mission aboard the Tiangong space station.